Endoscope

ABSTRACT

An endoscope has a first bending portion and a second bending portion. The first bending portion is the distal portion of an elongated insertion member and bent in four directions substantially perpendicular to the longitudinal axis of the insertion member. The second bending portion is bent in at least two directions substantially perpendicular to the longitudinal axis of the insertion member. The endoscope further includes a hand-held unit having a control section that is used to bend the first bending portion and second bending portion. The control section of the handheld unit has an angling knob that is used to bend the first bending portion, and a second angling lever that is used to bend the second bending portion.

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2000-302470, filed onOct. 2, 2000 and No. 2001-232165 filed on Jul. 31, 2001 in Japan, theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an endoscope, or moreparticularly, an endoscope having two bending portions of a firstbending portion and a second bending portion.

[0004] 2. Description of the Related Art

[0005] Endoscopes have an elongated insertion member thereof insertedinto the three-dimensionally complexly tortuous and narrow lumen of thestomach, the intestine, or any other organ of a living body or thethree-dimensionally complexly tortuous and narrow hollow of a machine inconformity with the shape of the lumen or hollow. The insertion memberof the endoscope must therefore be angled three-dimensionally finely.

[0006] For example, Japanese Examined Patent Application Publication No.5-16857 describes an endoscope having two bending portions of a firstbending portion and a second bending portion. The first bending portionis the distal portion of an elongated insertion member and has aplurality of joint pieces concatenated so that the joint pieces canrotate freely. The second bending portion is located at the proximal endof the first bending portion. A hand-held unit having a control sectionthat is used to bend the first bending portion and second bendingportion includes one angling mechanism. The sole angling mechanismenables selective bending of the first bending portion and secondbending portion.

[0007] However, the structure having the first bending portion thatbends in two directions like the one disclosed in the Japanese ExaminedPatent Application Publication No. 5-16857 has a drawback that when thefirst bending portion alone is used to perform the same examination asordinary endoscopic examination, the maneuverability of the structure ispoor.

SUMMARY OF THE INVENTION

[0008] An object of the present invention is to provide an endoscopethat offers excellent maneuverability and makes it possible to readilyachieve accurate observation or treatment.

[0009] Another object of the present invention is to provide anendoscope offering ease of bending of the same level as that anendoscope having one bending portion offers. Moreover, the endoscopeenables independent bending of two bending portions.

[0010] Still another object of the present invention is to provide anendoscope offering improved ease of observation with the distal portionof an insertion member faced a desired position.

[0011] According to the present invention, there is provided anendoscope having a first bending portion and a second bending portion.The first bending portion is the distal portion of an elongatedinsertion member and bend in four directions substantially perpendicularto the longitudinal axis of the insertion member. The second bendingportion is located at the proximal end of the first bending portion andbent in at least two directions substantially perpendicular to thelongitudinal axis of the insertion member.

[0012] According to the present invention, there is provided anendoscope having a first bending portion, a second bending portion, afirst control member, and a second control member. The first bendingportion is the distal portion of an elongated insertion member and bendin four directions substantially perpendicular to the longitudinal axisof the insertion member. The second bending portion is located at theproximal end of the first bending portion and bent in at least twodirections substantially perpendicular to the longitudinal axis of theinsertion member. The first control member is included in a hand-heldunit proximal to the insertion member and used to bend the first bendingportion. The second control member is included in the hand-held unitproximal to the insertion member and used to bend the second bendingportion.

[0013] Other features of the present invention and the advantagesthereof will be fully apparent from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 shows the overall configuration of an endoscope systemincluding an endoscope in accordance with an embodiment of the presentinvention;

[0015]FIG. 2 is a sectional view showing a bending portion of aninsertion member included in the endoscope shown in FIG. 1;

[0016]FIG. 3A and FIG. 3B are explanatory diagrams showing bendingpieces included in a first bending portion and a second bending portionrespectively;

[0017]FIG. 3A is an explanatory diagram showing a bending piece includedin the first bending portion;

[0018]FIG. 3B is an explanatory diagram showing a bending piece includedin the second bending portion;

[0019]FIG. 4 is an explanatory diagram showing the structure of a coilpipe;

[0020]FIG. 5 shows the appearances of a hand-held unit of the endoscopeand its surroundings;

[0021]FIG. 6 is an explanatory diagram showing the hand-held unit of theendoscope shown in FIG. 5 and held with a hand;

[0022]FIG. 7 shows the appearance of a hand-held unit of an endoscopethat has an angling knob, which is used to manipulate the second bendingportion, included in a second control subsection, and the appearance ofits surroundings;

[0023]FIG. 8 shows the appearance of a hand-held unit of an endoscopehaving a first control subsection and a second control subsection inwhich the axes of rotation cross at a right angle, and the appearance ofthe surroundings of the hand-held unit;

[0024]FIG. 9 shows the appearance of a hand-held unit of an endoscopethat has two angling knobs included in a second control subsection, andthe appearance of its surroundings;

[0025]FIG. 10A to FIG. 10C are plan views showing other examples of anangling knob included in the second control subsection;

[0026]FIG. 11 shows the appearance of another example of the anglingknob included in the second control subsection;

[0027]FIG. 12 is an explanatory diagram showing an insertion memberhaving a bending portion composed of a first bending portion and asecond bending portion by which bending angles are assumed when bent areset;

[0028]FIG. 13 is an explanatory diagram showing movements made by theinsertion member shown in FIG. 12;

[0029]FIG. 14 is an explanatory diagram showing other movements made bythe insertion member shown in FIG. 12;

[0030]FIG. 15A to FIG. 15C are explanatory diagrams showing the bendingportion shown in FIG. 12 and adapted to other endoscopes;

[0031]FIG. 15A is an explanatory diagram showing the insertion member ofa conventional enlarged-view endoscope;

[0032]FIG. 15B is an explanatory diagram showing the insertion member ofa conventional endoscope having two forceps passage channels;

[0033]FIG. 15C is an explanatory diagram showing the insertion member ofthe enlarged-view endoscope shown in FIG. 15A or the endoscope havingtwo forceps passage channels as shown in FIG. 15B, wherein the insertionmember has the bending portion shown in FIG. 7;

[0034]FIG. 16A and FIG. 16B are explanatory diagrams showing aninsertion member that has a second bending portion thereof made shorterthan a first bending portion thereof;

[0035]FIG. 16A shows an explanatory diagram showing the insertion memberwhose second bending portion is shorter than the first bending portionthereof;

[0036]FIG. 16B is an explanatory diagram showing a case where theinsertion member shown in FIG. 16A is inserted into a tortuous lumen;

[0037]FIG. 17A to FIG. 17C are explanatory diagrams showing a case wherean endoscope is used to observe the cardia of the stomach and itssurroundings;

[0038]FIG. 18A and FIG. 18B are explanatory diagrams showing aninsertion member that has a first bending portion thereof made shorterthan a second bending portion thereof;

[0039]FIG. 18A is an explanatory diagram showing the insertion memberwhose first bending portion is shorter than the second bending portionthereof;

[0040]FIG. 18B is an explanatory diagram showing a case where theinsertion member shown in FIG. 18A is inserted in a lumen that is hardlycurved;

[0041]FIG. 19 is an explanatory diagram showing a case where aninsertion member characterized in that the number of the directions inwhich a second bending portion thereof is bent is limited to a minimumnecessary number of directions is inserted in a lumen in which only aspecific object can be observed;

[0042]FIG. 20A to FIG. 20C are explanatory diagrams showing angulationwires that are arranged at positions in the second bending portion thatensure easy bending in oblique directions;

[0043]FIG. 20A is a sectional view showing angulation wire locksincluded in the second bending portion in order to lock two second wiresthat are arranged at an Up position and a Right position;

[0044]FIG. 20B is a sectional view showing angulation wire locksincluded in the second bending portion in order to lock two second wiresthat are arranged at Down and Left positions;

[0045]FIG. 20C is a sectional view showing angulation wire locksincluded in the second bending portion in order to lock two second wiresthat are arranged at an intermediate position between Up and Rightpositions and an intermediate position between Down and Left positions;

[0046]FIG. 21 is an explanatory diagram showing the insertion member ofa conventional endoscope whose bending portion is composed of a firstbending portion and a second bending portion;

[0047]FIG. 22 is a schematic explanatory diagram showing an insertionmember whose bending portion includes a second bending portion that canbe straightened; and

[0048]FIG. 23 is a schematic explanatory diagram showing an insertionmember that is a variant of the insertion member shown in FIG. 22.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] An embodiment of the present invention will be described withreference to the drawings below.

[0050]FIG. 1 to FIG. 9 are concerned with an embodiment of the presentinvention.

[0051] As shown in FIG. 1, an endoscope system 1 having the embodimentof the present invention consists mainly of an electronic endoscope(hereinafter simply an endoscope) 2, a light source apparatus 3, a videoprocessor 4, and a monitor 5. The electronic endoscope 2 has an imagepick-up means that is not shown. The light source apparatus 3 isconnected to the endoscope 2 so that it can be disconnected freely, andsupplies illumination light to the endoscope 2. The video processor 4 isconnected to the endoscope 2 so that it can be disconnected freely. Thevideo processor 4 controls the image pick-up means included in theendoscope 2 and processes a signal produced by the image pick-up meansto transmit a standard video signal. The monitor 5 displays anendoscopic image according to a signal processed by the video processor4.

[0052] A VTR deck, a video printer, a video disk drive, an image filerecording apparatus, or the like, not shown, can be connected to thevideo processor 4.

[0053] The endoscope 2 has an elongated insertion member 11 that isinserted into a region to be observed. A hand-held unit 12 is located atthe proximal end of the insertion member 11. The hand-held unit 12includes a control section 12 a that is used to bend first and secondbending portions that will be described later.

[0054] A universal cord 13 is extended from the lateral side of thehand-held unit 12. A signal cable that is routed to the image pick-upmeans which is not shown and a light guide over which illumination lightis propagated are contained in the universal cord 13.

[0055] A connector 14 is attached to the end of the universal cord 13.The connector 14 is coupled to the light source apparatus 3 andconnected to the video processor 4 such that it can be connected anddisconnected freely.

[0056] A distal part 21 is located at the distal end of the insertionmember 11. A bending portion 22 capable of freely bending is located atthe proximal end of the distal part 21. A flexible tube 23 is located atthe proximal end of the bending portion 22. The flexible tube 23 isformed with an elongated member that is soft and tubular.

[0057] An image pick-up unit in which a solid-state image pick-up devicethat is not shown, such as, a CCD and a circuit board for driving thesolid-state image pick-up device are incorporated is included as theimage pick-up means in the distal part 21. The distal end of the lightguide is extended to the distal part 21, whereby illumination lightpropagated from the light source apparatus 3 is radiated to a region tobe observed in a body cavity. The region to be observed is thusilluminated.

[0058] The bending portion 22 is composed of two bending portions, thatis, a first bending portion 24 that is the distal half of the bendingportion 22 and a second bending portion 25 that succeeds the firstbending portion 24.

[0059] To begin with, the structure of the bending portion 22 will bedescribed in conjunction with FIG. 2 to FIG. 5.

[0060] As shown in FIG. 2, the first bending portion 24 and secondbending portion 25 each has a plurality of bending pieces 31concatenated so that the bending pieces can rotate freely. The pluralityof bending pieces 31 are sheathed with a bending braid 32 made bycylindrically weaving thin wires. The bending braid 32 is sheathed witha bending rubber 33 and thus kept watertight.

[0061] The bending braid 32 and bending rubber 33 may be used to sheathethe bending portion 22 composed of the first bending portion 24 andsecond bending portion 25 over the whole length of the bending portion22. Otherwise, the first bending portion 24 and second bending portion25 may be sheathed with the bending braid 32 and bending rubber 33independently of each other.

[0062] First wires 34 used to pull and bend the first bending portion 24are extended from the distal end of the first bending portion 24.

[0063] Second wires 35 used to pull and bend the second bending portion25 are extended from the distal end of the second bending portion 25.

[0064] The first wires 34 are passed through first coil pipes 36 fixedto the distal end of the second bending portion 25, and thus routed to afirst control subsection 42, which will be described later, by way ofthe insertion member 11.

[0065] Moreover, the second wires 35 are passed through second coilpipes 37 fixed to the distal end of the flexible tube 23, and thusrouted to a second control subsection 44, which will be described later,by way of the insertion member 11.

[0066] Furthermore, the thickness of the portion of the bending rubber33 with which the second bending portion 25 is sheathed is smaller thanthe thickness of the portion thereof with which the first bendingportion 24 is sheathed. Consequently, the second bending portion of thebending portion 22 is more easily bent. Even if a larger number ofbuilt-in components must be put in the second bending portion 25, theouter diameter of the second bending portion 25 need not be increased.The ease of bending characterizing the bending portion 22 will thereforenot deteriorate.

[0067] Generally, when the bending portion 22 is bent, a larger load isoften imposed on the second bending portion 25 than on the first bendingportion 24. This is because the second bending portion 25 accommodates alarger number of built-in components.

[0068] For this reason, the bending pieces 31 constituting the secondbending portion 25 of the bending portion 22 are, as shown in FIG. 3Aand FIG. 3B, made thicker than those constituting the first bendingportion 24.

[0069] In other words, bending pieces 31 b used to construct the secondbending portion 25 of the bending portion 22 as shown in FIG. 3B aremade thicker than bending pieces 31 a used to construct the firstbending portion 24 as shown in FIG. 3A.

[0070] Consequently, even when a larger magnitude of force is applied tothe second bending portion 25 than to the first bending portion 24, thebending pieces 31 constituting the second bending portion 25 hardlydeform. Thus, a bending angle the second bending portion 25 assumes whenbent is set will not get smaller than a bending angle it assumes in aninitial state.

[0071] Moreover, coil pipes used as the first coil pipes 36 and secondcoil pipes 37 are made by, as shown in FIG. 4, finely winding a thinwire so that adjoining portions of the wire will be closely in contactwith each other. Owing to this structure, the whole length of the coilpipe may be shortened with application of a load of compression. Forthis reason, the diameter of a wire used to make the second coil pipes31 fixed to the proximal end of the second bending portion 25 that mustincur a larger load is made larger than the diameter of a wire used tomake the first coil pipes 36. Consequently, the second coil pipes 37 arehardly compressed because they are made using a thicker wire than thefirst coil pipes 36 are. Therefore, even if a larger magnitude of forceis applied to the second bending portion 25 than to the first bendingportion 24, the coil pipes will not contract. Thus, a bending angle thesecond bending portion assumes when bent is set will not get smallerthan the one it assumes in an initial state.

[0072] According to the present embodiment, the control section 12 a ofthe hand-held unit 12 consists of the first control subsection 42 andsecond control subsection 44. The first control subsection 42 is used tobend the first bending portion 24. The second control subsection 44 isused to bend the second bending portion 25. Owing to the structure, thefirst bending portion 24 and second bending portion 25 can be bentindependently of each other.

[0073] The first control subsection 42 includes, as shown in FIG. 5,angling knobs 42 a and 42 a′ and first locking levers 42 b and 42 b′.The angling knobs 42 a and 42 a′ are used to bend the first bendingportion 24. The first locking levers 42 b and 42 b′ are used to lock theangling knobs 42 a at desired angular positions.

[0074] The second control subsection 44 includes, as shown in FIG. 5, asecond angling lever 44 a used to bend the second bending portion 25 anda second locking lever 44 b used to lock the second angling lever 44 aat a desired angular position.

[0075] The control section 12 a has an electric switch subsection 43that includes remote switches 43 a used to instruct the video processor4 to freeze or unfreeze a view image.

[0076] The angling knob 42 a is a knob used to bend the first bendingportion 24 in Up and Down directions. The angling knob 42 a′ is a knobused to bend the first bending portion 24 in Right and Left directions.

[0077] The first locking lever 42 b is a lever used to lock the anglingknob 42 a at a desired angular position. The first locking lever 42 b′is a knob used to lock the angling knob 42 a′ at a desired angularposition.

[0078] Furthermore, the first control subsection 42 includes anaeration/perfusion button 42 c used to instruct aeration or perfusionand a suction button 42 d used to instruct suction.

[0079] The endoscope 2 having the foregoing components is used toperform endoscopic examination.

[0080] In general, an operator holds, as shown in FIG. 6, the hand-heldunit 12 with his/her left hand so as to angle the endoscope.

[0081] In this case, for example, the hand-held unit 12 is borne withthe root of the thumb of the left hand and the ring finger and littlefinger of the left hand. The angling knob 42 a and second angling lever44 a are manipulated using the thumb. The index finger and middle fingerare also used to manipulate the angling knob 42 a and second anglinglever 44 a when these fingers are not manipulating the remote switches43 a and the buttons including the aeration/perfusion button 42 c andsuction button 42 d.

[0082] When an operator wants to bend the first bending portion 24, theoperator bears the hand-held unit 12 with the root of the thumb of theleft hand and the ring finger and little finger thereof. The operatorthen manipulates the angling knob 42 a using the thumb, index finger, ormiddle finger thereof. At this time, the angling knob 42 a lies withinreach of the thumb, index finger, or middle finger.

[0083] Moreover, when an operator wants to bend the second bendingportion 25, the operator manipulates the second angling lever 44 a withhis/her right hand that does not hold the hand-held unit 12.

[0084] The thumb, index finger, or middle finger may be stretched to aposition that is usually beyond reach of it in order to manipulate thesecond angling lever 44 a.

[0085] When the remote switches 43 a are used or endoscopic treatment iscarried out, the first locking levers 42 b and 42 b′ and the secondlocking lever 44 b may be used to lock the angling knobs 42 a and 42 a′and the second angling lever 44 a at desired angular positions. In thiscase, the thumb can be separated from the hand-held unit, and theendoscope can be manipulated with the insertion member retained in adesired bent state.

[0086] Moreover, the second control subsection 44 is separated from thefirst control subsection 42 with the electric switch subsection 43between them. When the angling knob 42 a is manipulated, the fingerswith which the angling knob is manipulated will not come in contact withthe second angling lever 44 a.

[0087] The second angling lever 44 a may be, as shown in the plan viewof FIG. 10A, jutted out in a direction opposite to the direction of theangling knobs 42.

[0088] The foregoing structure may be modified in consideration of easewith which the second angling lever 44 a can be manipulated with, forexample, the right hand, so that the second angling lever 44 a will jutout towards the angling knobs 42 as shown in FIG. 10B and FIG. 10C.

[0089] Referring to FIG. 5 and FIG. 6, the second angling lever 44 athat is a lever used to bend the second bending portion 25 is includedin the second control subsection 44. However, the present invention isnot limited to the second angling lever 44 a. As shown in FIG. 7, whenthe second bending portion can be bend in freely selected directions, anangling knob 44 c that resembles the angling knob 42 a may besubstituted for the second angling lever 44 a.

[0090] The axes of rotation in the first control subsection 42 andsecond control subsection 44 may extend parallel to each other as shownin FIG. 5. Alternatively, the axes of rotation may meet at an angle asshown in FIG. 8. Referring to FIG. 8, the axes of rotation in the firstcontrol subsection 42 and second control subsection 44 cross at rightangles.

[0091] Moreover, when the second bending portion 25 is designed to beable to bend in four directions, the second control subsection 44includes two angling knobs 44 c as shown in FIG. 9. The second bendingportion 25 can thus be bent in four directions.

[0092] Consequently, in the endoscope 2 in accordance with the presentembodiment, the first and second bending portions 24 and 25 can be bentindependently of each other. The two bending portions can be handled inthe same manner as an ordinary bending portion is. The endoscope 2 ofthe present embodiment offers improved ease of bending.

[0093] The endoscope 2 of the present embodiment has the second controlsubsection 44 separated from the first control subsection 42.Consequently, when the first control subsection 42 alone is used, thesecond control subsection will not annoy an operator. The endoscopeoffers ease of bending of the same level as a normally employedendoscope having one bending portion does.

[0094] Furthermore, the endoscope 2 of the present embodiment has thesecond control subsection 44 and first control subsection 42 separatedfrom each other with the electric switch subsection 43 between them.Consequently, the maneuverability offered by the endoscope will not bepoorer than the maneuverability offered by an ordinary endoscope. Inaddition, when the first control subsection 42 and electric switchsubsection 43 are used, the second control subsection 44 will not bemanipulated incorrectly.

[0095] In the endoscope 2 of the present embodiment, the axes ofrotation in the first control subsection 42 and second controlsubsection 44 meet at an angle. Consequently, when the first controlsubsection 42 is held with one hand and the second control subsection 44is manipulated with the other hand, the second control subsection 44 canbe manipulated easily.

[0096] The endoscope 2 in accordance with the present embodiment is anelectronic endoscope having the image pickup unit incorporated in thedistal part 21 of the insertion member 11. Alternatively, the presentinvention may be implemented in an electronic endoscope in which animage guide that is not shown is run through the insertion member 11 andan object image propagated along the image pick-up guide is picked up byan image pick-up unit incorporated in the control section 12 a.Moreover, the present invention may be implemented in a so-calledoptical endoscope in which an object image propagated along the imageguide is viewed through an eyepiece unit mounted on the control section12 a. In any case, the endoscope has the bending portion 22 composed ofthe first bending portion 24 and second bending portion 25.

[0097] The present invention is not limited to the aforesaid embodiment,but can be modified in various aspects with the gist of the presentinvention left unchanged.

[0098] For example, as shown in FIG. 11, the second angling lever 44 amay be located at a position at which a forceps lift lever is usuallylocated in an ordinary endoscope.

[0099] As far as observation of an intracavitary region is concerned,observing a region to be observed from the front side thereof is veryhelpful in a viewpoint of producing a clear image devoid of deformation.

[0100] When an endoscope has the same structure as the aforesaid one,that is, the elongated insertion member 11 has the bending portion 22composed of the first bending portion 24 and second bending portion 25,the first bending portion 24 and second bending portion 25 are bentindependently of each other. Thus, the distal part 21 of the insertionmember can be faced a region to be observed.

[0101] For example, the insertion member 11 may be in close contact withthe intracavitary wall as shown in FIG. 21. In this case, the secondbending portion 25 is bent upward by an angle θ with respect to thelongitudinal axis of the insertion member 11. At the same time, thefirst bending portion 24 is bent downwards by an angle θ+90° withrespect to the longitudinal axis of the insertion member 11.Consequently, the distal part 21 of the insertion member 11 is angled toface a region to be observed that is located on an intracavitary wall.

[0102]FIG. 21 is an explanatory diagram showing the insertion member ofa conventional endoscope having a bending portion composed of a firstbending portion and a second bending portion.

[0103] However, assume that the insertion member 11 is in close contactwith an intracavitary wall, and that the distal part 21 of the insertionmember is faced the intracavitary wall. In this case, the distal part 21is located near an extension of the longitudinal axis of the flexibletube 23 (which is in close contact with the intracavitary wall) of theinsertion member 11. Consequently, the distal part 21 cannot have apredetermined distance from the region to be observed.

[0104] If the distal part 21 cannot be separated from a region to beobserved by a predetermined distance, it is hard to observe the regionto be observed during endoscopic examination. Although the predetermineddistance cannot be preserved, if an attempt is made to performendoscopic treatment, a therapeutic instrument or the like may not beable to be projected from the distal part 21 towards an intracavitarywall. Consequently, the endoscopic treatment fails.

[0105] In order to solve the above problem, it is conceivable toincrease the dimension of the second bending portion 25. The secondbending portion 25 is bent appropriately in order to raise the firstbending portion 24 relative to the intracavitary wall, whereby thepredetermined distance may be preserved. However, this structure has adrawback that the overall length of the bending portion 22 is too large.

[0106] The bending portion 22 has, as described in conjunction with FIG.2, the plurality of bending pieces 25 sheathed with the braid 32 andbending rubber 33. The surface of the bending portion 22 is thereforefinely irregular and hardly smooth. The bending portion 22 musttherefore have a minimum necessary length.

[0107] There is therefore a long-persistent demand for an endoscope thatoffers improved ease of observation and treatment when the distal part21 is faced an intracavitary wall with both the first bending portion 24and second bending portion 25 bent.

[0108] Referring to FIG. 12 to FIG. 20C, an example of the structure ofan endoscope including two bending portions will be described below.

[0109]FIG. 12 to FIG. 20C show the example of the structure of anendoscope including two bending portions.

[0110] As shown in FIG. 12, the first bending portion 24 and secondbending portion 25 are bent, and the distal part 21 of the insertionmember is thus angled in a direction perpendicular to the longitudinalaxis of the insertion member 11, that is, faced an intracavitary wall.In this state, bending angles the first bending portion 24 and secondbending portion 25 that constitute the bending portion 22 assume whenbent is set are determined so that the distal part 21 will always lieabove an extension of the longitudinal axis of the insertion member 11(so that the distal part 21 can be distanced from a region to beobserved).

[0111] Referring to FIG. 12, the bending angle the second bendingportion 25 assumes when bent, θ, is set substantially to 90° and thebending angle the first bending portion 24 assumes when bent, (θ+90°),is set substantially to 180°.

[0112] The thus-structured bending portion 22 is adapted to aconventional enlarged-view endoscope 2A that has, as shown in FIG. 15A,an image pick-up unit (not shown), of which focus can be changed fromone to another, incorporated in the distal part 21. Otherwise, thebending portion 22 is adapted to a conventional endoscope 2B having, asshown in FIG. 15B, two forceps passage channels 51.

[0113] As shown in FIG. 15A, the conventional enlarged-view endoscope 2Ahas the insertion member 11 that includes one bending portion.Therefore, the distal part 21 is located on or near an extension of thelongitudinal axis of the flexible tube 23 (that is in close contact withan intracavitary wall) along the intracavitary wall. It is thereforehard to observe a lesion located tangentially to the intracavitary wall.

[0114] Referring to FIG. 15B, a predetermined distance cannot bepreserved between the distal part 21 of the insertion member of theendoscope 2B having two forceps passage channels 51 and a region to beobserved. A therapeutic instrument 52 or the like cannot be projectedfrom the distal part 21. It is therefore hard to perform endoscopictreatment.

[0115] Now, when the bending portion 22 is structured as shown in FIG.12, the distance between the distal part 21 and a region to be observedcan be adjusted as shown in FIG. 15c. Moreover, two therapeuticinstruments can be used for endoscopic treatment.

[0116] As shown in FIG. 13, when a lesion is observed, the first bendingportion 24 and second bending portion 25 are bent, and the secondlocking lever 44 b is manipulated in order to lock the second anglinglever 44 a at a desired angular position. Consequently, the secondbending portion 25 can be retained in a desired bent state. The firstbending portion 24 is bent vertically and laterally with the secondangling lever 44 a locked. Eventually, the distal part of the endoscopecan be angled in the directions of arrows with the lesion and distalpart distanced from each other.

[0117] In short, observation can be continued with the relativepositions of the lesion and the distal part varied.

[0118] Furthermore, as shown in FIG. 14, the first locking levers 42 band 42 b′ are manipulated to lock the bending knobs 42 at desiredangular positions. Consequently, the first bending portion 24 isretained in a desired bent state. In this state, the second bendingportion 25 is bend in two directions. Thus, the distal part of theendoscope can be angled in the directions of arrows while faced thelesion.

[0119] In short, the distance between the lesion and the distal part ofthe endoscope can be adjusted with the distal part angled to the lesion.

[0120] As shown in FIG. 13 and FIG. 14, the first bending portion 24 andsecond bending portion 25 can be retained in respective bent states.This leads to improved ease of manipulation offered for endoscopicobservation.

[0121] Furthermore, the bending portion 22 may be designed such that thesecond bending portion 25 will be shorter than the first bending portion24 as shown in FIG. 16A. For example, when the endoscope is used toobserve a tortuous lumen such as the lumen of the large intestine, evenif the second bending portion 25 is bent, the second bending portion 25will not interfere with the intestinal wall but the bending portion 22can be entirely moved.

[0122] In contrast with FIG. 16A, FIG. 18A shows the bending portionhaving the second bending portion 25 made longer than the first bendingportion 24. As shown in FIG. 18B, when the bending portion is insertedin a lumen that is almost not at all curved, for example, the lumen ofthe stomach, ease of insertion or treatment can be improved. Namely, atherapeutic instrument can be inserted easily during endoscopictreatment, or the distal part 21 of the insertion member can be angledeasily finely.

[0123] As shown in FIG. 17A, when an endoscope has only one bendingportion, the bending portion can be bent in order to position the distalpart closely to the cardia of the stomach. However, the cardia and itssurroundings are observed obliquely. It is therefore hard to view thecardia and its surroundings from the front sides thereof.

[0124] As shown in FIG. 17B, when the second bending portion 25 issomewhat long, since the second bending portion 25 must be fully juttedout of the esophagus, the first bending portion 24 recedes from thecardia of the stomach. Therefore, even if an attempt is made to bend thefirst bending portion in order to observe the cardia and itssurroundings, the distance between the distal part of the endoscope andthe cardia is too large to achieve observation successfully.

[0125] Now, in an endoscope shown in FIG. 17C, the dimension of thesecond bending portion 25 in a direction of insertion is smaller thanthe dimension of the first bending portion 24 therein. When thedimensions of the first and second bending portions 24 and 25 in thedirection of insertion are thus set, if the first and second bendingportions 24 and 25 are bent in order to observe the cardia of thestomach and its surroundings, the distal part of the endoscope can bepositioned closely to the cardia. This results in successfulobservation.

[0126] As shown in FIG. 19, an endoscope may be used exclusively toobserve, for example, the duodenum. In this case, the second bendingportion 25 is made bendable in only one direction (an Up or Downdirection). Like this, the number of the bendable directions of thesecond bending portion 25 is limited to a minimum necessary number ofdirections. This leads to a simplified angling mechanism.

[0127]FIG. 19 shows a case where the distal part 21 of the insertionmember is made to approach the duodenal papilla.

[0128] When the duodenal papilla or any other region of the duodenum isincised, the distal end of an endoscope should be made to approachobliquely for more successful treatment.

[0129] In this case, the second wires 35 to be pulled in order to bendthe second bending portion 25 may be arranged as shown in FIG. 20A toFIG. 20C.

[0130] As shown in FIG. 20A and FIG. 20B, the second wires 35 lyingthrough the second bending portion 25 may be arranged at Up and Rightpositions or Down and Left positions so that the second bending portion25 can be easily bent obliquely.

[0131] As shown in FIG. 20C, the second wires 35 lying through thesecond bending portion 25 may be arranged at an intermediate positionbetween the Up and Right positions and an intermediate position betweenthe Down and Left positions.

[0132] As far as the aforesaid endoscope whose elongated insertionmember 11 has the bending portion 22 is concerned, the second bendingportion 25 of the bending portion 22 is first bent. Namely, the one ofthe second wires 35 described in conjunction with FIG. 2, which islocated at the Up position, is pulled in order to bend the secondbending portion 25 in the Up direction. If the second bending portion 25is straightened thereafter, since restoring force exerted by the bendingrubber 33 with which the second bending portion 25 is sheathed is weak,the one of the second wires 35 which is located at the Down positionmust be pulled. Therefore, an angling mechanism is very complex.

[0133] There is therefore a demand for an endoscope having a simplestructure and having the second bending portion 25 capable of beingstraightened.

[0134] Referring to FIG. 22 and FIG. 23, an example of the structure ofan endoscope whose second bending portion can be straightened will bedescribed below.

[0135] As shown in FIG. 22, the first bending portion 24 of the bendingportion 22 has a plurality of bending pieces 31 concatenated so that thebending pieces can rotate freely. The concatenated bending pieces 31 aresheathed with the bending braid 32 made by cylindrically weaving thinwires, and then covered with the bending rubber 33.

[0136] The second bending portion 25 has, similarly to the first bendingportion 24, the plurality of bending pieces 31 concatenated so that thebending pieces can rotate freely. The bending pieces 31 are sheathedwith the bending braid 32. The bending braid 32 is coated with aresilient resin 61 such as polyester which is the same resin as thatadopted for the flexible tube 23.

[0137] Consequently, the second bending portion 25 has the bending braid32 coated with the resilient resin 61 that is the same resin as thatadopted for the flexible tube 23. Therefore, the second bending portion25 that has been bent can be straightened by merely slackening one ofthe second wires 35. Namely, the second wire 35 to be slackened is asecond wire that has been pulled in order to bend the second bendingportion 25 in a direction that runs externally parallel to the secondwire.

[0138] Moreover, the second wires 35 used to bend the second bendingportion 25 may lie, as shown in FIG. 23, alone at one position, so thatthe second bending portion 25 can be bent in only one direction.

[0139] As described in conjunction with FIG. 2, the second wires 35 arepassed through the second coil pipes 37 inside the flexible tube 23 upto the proximal end of the second bending portion 25.

[0140] The second bending portion 25 has the same structure as, forexample, the flexible tube 23 (for example, as shown in FIG. 22, moldedusing the same resin 61 as that adopted for the flexible tube 23). Thus,the second bending portion 25 is easily straightened.

[0141] Consequently, when the second wires 35 are not tensioned, thesecond bending portion 25 is automatically straightened. Only one of thesecond wires 35 can therefore be used to bend or straighten the secondbending portion 25. Herein, a position of the second wire defines onedirection in which the second bending portion 25 can be bent.

[0142] The present invention is not limited to the aforesaid embodimentbut can be modified in various aspects with the gist of the presentinvention left unchanged.

[0143] As described so far, according to the present invention, there isprovided an endoscope whose first bending portion can be bent in fourdirections and whose second bending portion can be bent in twodirections. The endoscope offers excellent maneuverability of the samelevel as that an widely adopted endoscope having one bending portionoffers. In short, the present invention provides an endoscope havingboth the merit of an endoscope having one bending portion and the meritof an endoscope having two bending portions.

[0144] According to the present invention, it is apparent that a widerange of different embodiments can be formed based on the inventionwithout a departure from the spirit and scope of the invention. Thepresent invention is limited to the appended claims but not restrictedto any specific embodiment.

What is claimed is:
 1. An endoscope comprising: a first bending portionthat is the distal portion of an elongated insertion member and bent infour directions substantially perpendicular to the longitudinal axis ofthe insertion member; and a second bending portion located at theproximal end of said first bending portion and bent in at least twodirections substantially perpendicular to the longitudinal axis of theinsertion member.
 2. The endoscope according to claim 1, wherein abending angle said first bending portion assumes when bent is set islarger than a bending angle said second bending portion assumes whenbent is set.
 3. The endoscope according to claim 1, wherein said secondbending portion is passively bent in four directions substantiallyperpendicular to the longitudinal axis of said insertion member.
 4. Theendoscope according to claim 1, wherein the directions in which saidsecond bending portion is bent are agreed with two directions out of thedirections in which said first bending portion is bent, said twodirections are opposite to each other.
 5. The endoscope according toclaim 1, wherein a bending angle said first bending portion assumes whenbent is set and a bending angle said second bending portion assumes whenbent is set are determined so that when said second bending portion isbent by an angle θ and said first bending portion is bent by θ+90° ormore in a direction opposite to the direction in which said secondbending portion is bent, and when the distal portion of said insertionmember is angled in a direction substantially perpendicular to thelongitudinal axis of said insertion member, the distal portion of saidinsertion member will be distanced from a tangent to the longitudinalaxis of said insertion member.
 6. The endoscope according to claim 5,wherein the overall length of said first bending portion is larger thanthe overall length of said second bending portion.
 7. The endoscopeaccording to claim 5, wherein the overall length of said second bendingportion is larger than the overall length of said first bending portion.8. An endoscope comprising: a first bending portion that is the distalportion of an elongated insertion member and bent in four directionssubstantially perpendicular to the longitudinal axis of said insertionmember; a second bending portion located at the proximal end of saidfirst bending portion and bent in at least two directions substantiallyperpendicular to the longitudinal axis of said insertion member; a firstcontrol member included in a hand-held unit proximal to said insertionmember and used to bend said first bending portion; and a second controlmember included in the hand-held unit proximal to said insertion memberand used to bend said second bending portion.
 9. The endoscope accordingto claim 8, wherein an bending angle said first bending portion assumeswhen bent is set is larger than a bending angle said second bendingportion assumes when bent is set.
 10. The endoscope according to claim8, wherein said second bending portion is passively bent in fourdirections substantially perpendicular to the longitudinal axis of saidinsertion member.
 11. The endoscope according to claim 8, wherein thedirections in which said second bending portion is bent aresubstantially agreed with two opposite directions out of the directionsin which said first bending portion is bent.
 12. The endoscope accordingto claim 8, wherein an angle said first bending portion assumes whenbent is set and an angle said second bending portion assumes when bentis set are determined so that when said second bending portion is bentby an angle θ and said first bending portion is bent by θ+90° or more ina direction opposite to the direction in which said second bendingportion is bent, and when the distal portion of said insertion member isangled substantially perpendicularly to the longitudinal axis of saidinsertion member, the distal portion of said insertion member will bedistanced from a tangent to the longitudinal axis of said insertionmember.
 13. The endoscope according to claim 8, wherein the axis ofrotation of said first control member and the axis of rotation of saidsecond control member are extended in different directions.
 14. Theendoscope according to claim 8, wherein: said first control member isarranged so that when said hand-held unit is held, said first controlmember will lie within reach of a finger of the hand with which saidhandheld unit is held; and said second control member is arranged sothat when said hand-held unit is held, said second control member willlie beyond reach of a finger of the hand with which said hand-held unitis held.
 15. The endoscope according to claim 8, wherein an electricswitch subsection used to give predetermined instructions is interposedbetween said first control member and said second control member. 16.The endoscope according to claim 8, wherein said first control member islocated in the distal part of a control section, and said second controlmember is located in the proximal part thereof.
 17. The endoscopeaccording to claim 8, wherein: said first control member is arranged sothat when said hand-held unit is held with the left hand, said firstcontrol member will lie within reach of a finger of the left hand withwhich said hand-held unit is held; and said second control member isarranged so that when said hand-held unit is held with the left hand,said second control member will lie beyond reach of a finger of the lefthand with which said hand-held unit is held, and will be manipulatedwith a finger of the right hand.
 18. The endoscope according to claim 8,wherein said first control member includes a first Right/Left controlmember that is used to bend said first bending portion in a Right orLeft direction, and a second Up/Down control member that is used to bendsaid first bending portion in an Up or Down direction.
 19. The endoscopeaccording to claim 8, wherein said second control member includes afirst Right/Left control member that is used to bend said second bendingportion in a Right or Left direction, and a second Up/Down controlmember that is used to bend said second bending portion in an Up or Downdirection.
 20. The endoscope according to claim 12, wherein the overalllength of said first bending portion is larger than the overall lengthof said second bending portion.
 21. The endoscope according to claim 12,wherein the overall length of said second bending portion is larger thanthe overall length of said first bending portion.
 22. The endoscopeaccording to claim 13, wherein the axis of rotation of said firstcontrol member and the axis of rotation of said second control memberare extended substantially parallel to each other.
 23. The endoscopeaccording to claim 13, wherein the axis of rotation of said firstcontrol member and the axis of rotation of said second control memberare extended substantially perpendicularly to each other.
 24. Theendoscope according to claim 15, wherein said electric switch subsectionseparates said first control member and said second control member fromeach other.
 25. The endoscope according to claim 16, wherein amanipulated portion of said first control member and a manipulatedportion of said second control member face in the same direction.